Sheet-processing machine comprising at least one transport unit and method for the straight-tracking guidance of at least one conveyor belt of a sheet-processing machine

ABSTRACT

In some examples, a sheet-processing machine includes a transport unit for transporting sheets. The transport unit includes a feed roller configured as an infeed roller and a feed roller configured as a diverting roller, which define a transport plane of sheets. At least two further feed rollers of the transport unit are arranged outside the transport plane. At least one feed roller of the at least two further feed rollers is configured as a pivoting roller that pivots and/or that can be pivoted about a pivot axis. The pivot axis of the pivoting roller is an axis that is normal of an axis of rotation of the pivoting roller, and the pivoting roller is configured to automatically pivot about the pivot axis.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is the US national phase, under 35 USC § 371, of PCT/EP2022/062134, filed on May 5, 2022, published as WO 2022/243051 A1 on Nov. 24, 2022, and claiming priority to DE 10 2021 112 924.9, filed May 19, 2021, and all of which are expressly incorporated by reference herein in their entireties.

TECHNICAL FIELD

Some examples relate to a sheet-processing machine comprising at least one transport unit that includes at least one feed roller configured as an infeed roller, and at least one feed roller configured as a diverting roller, which define a transport plane of sheets. At least two further feed rollers of the transport unit are arranged outside the transport plane. At least one feed roller of the at least two further feed rollers is configured as a pivoting roller that pivots and/or that can be pivoted about a pivot axis. The pivot axis of the pivoting roller is an axis normal of an axis of rotation of the pivoting roller.

Some examples relate to a method for the straight-tracking guidance of at least one conveyor belt of a sheet-processing machine. The at least one conveyor belt is guided around at least one feed roller configured as an infeed roller, and at least one feed roller configured as a diverting roller. The at least one infeed roller and the at least one diverting roller define a transport plane of sheets. The at least one conveyor belt is guided around at least two further feed rollers of the transport unit outside the transport plane. At least one feed roller of the at least two further feed rollers is configured as a pivoting roller that pivots about a pivot axis. The pivot axis of the pivoting roller is an axis normal of an axis of rotation of the pivoting roller.

BACKGROUND

Sheets are transported in sheet-processing machines, for example printing presses or die-cutting machines, by means of transport units. One embodiment of the transport units comprises conveyor belts. In a feeder, for example, sheets are separated from a pile of sheets and fed to downstream units by means of a transport unit configured as a belt table. To ensure stable transport of the sheets, straight-tracking guidance of the conveyor belt must be ensured, without the conveyor belt running laterally off its guiding rollers. Lateral run-off of the conveyor belt is to be avoided since this results in lateral fraying and/or destruction of the conveyor belt.

DE 20 2006 001 851 U1 discloses a device at a suction belt table for transporting sheet-format material from a sheet feeder to a sheet-processing machine using one or more conveyor belts, wherein the conveyor belts can be driven at least by way of deflection rollers and are continuously guided around the belt table and can be tensioned by means of tensioning devices. Deliberate lateral guidance of the conveyor belt is achieved by means of an elevation, referred to as crowning, in a partial region of a tensioning roller with a cross-sectional contour that extends symmetrically for expanding the guide range.

US 2009/0145729 A1 teaches a device for correcting a skewed position of a revolving conveyor belt, which is guided between a roller driving the conveyor belt and a further roller in a tensioned state. For this purpose, a correcting roller, which is in contact with the conveyor belt, is provided, the angle of inclination of which is adjusted by way of a mechanism. The mechanism laterally engages on one of the mounts of the correcting rollers and comprises a driving body, in particular a motor, that is activated by a control unit, and a conversion mechanism, in particular comprising a cam mechanism, which converts the driving movement of the driving body into an inclination of the correcting roller. The driving body carries out the driving movement intermittently, enabling rapid and precise control of the angle of inclination.

A device for infeeding sheets is known from DE 10 2019 122 496 A1, wherein a feed roller of a suction belt table is configured as a dancer roller. The dancer roller has two degrees of freedom and enables both a tilting movement of the rollers, transversely to the transport direction, and a rotational movement in the transport direction. The dancer roller comprises a shaft and a hollow-cylindrical roller body, which is arranged rotatably about the shaft, coaxially to the shaft, and a self-aligning bearing acting between the shaft and the roller body.

EP 3 196 036 A1 discloses a belt conveyor system comprising an endless belt, the belt extending around three rollers. In addition, a steering roller is arranged within an inner volume of the three rollers. The steering roller is configured to control the lateral position of the belt transversely to the revolving path. A first rotational position of the steering roller about a first axis of rotation is controlled, and a second rotational position of the steering roller about a second axis of rotation is controlled. The rotational positions of the steering roller are adjusted by means of activated actuators.

SUMMARY

It is an object of some examples herein to provide a sheet-processing machine comprising at least one transport unit and a method for the straight-tracking guidance of at least one conveyor belt of a sheet-processing machine.

The object is achieved according to some examples by at least one pivoting roller that pivots automatically about the pivot axis.

A sheet-processing machine comprising at least one transport unit for transporting sheets is devised. The at least one transport unit comprises at least one feed roller configured as an infeed roller, and at least one feed roller configured as a diverting roller, which define a transport plane of sheets. At least two further feed rollers of the transport unit are arranged outside the transport plane. At least one further feed roller of the at least two further feed rollers, is configured as a pivoting roller that pivots and/or can be pivoted about a pivot axis. The pivot axis of the pivoting roller is an axis normal of the axis of rotation of the pivoting roller.

A method for the straight-tracking guidance of at least one conveyor belt of a sheet-processing machine is devised. The at least one conveyor belt is guided around at least one feed roller configured as an infeed roller, and at least one feed roller configured as a diverting roller. The at least one infeed roller and the at least one diverting roller define a transport plane of sheets. The at least one conveyor belt is guided around at least two further feed rollers of the transport unit outside the transport plane. At least one further feed roller of the at least two further feed rollers is configured as a pivoting roller that pivots about a pivot axis. The pivot axis of the pivoting roller is an axis normal of the axis of rotation of the pivoting roller.

The advantages to be achieved with the invention are, in particular, that the quality of the sheet transport is enhanced. In particular, the uniformity of the sheet transport transversely to the transport direction is enhanced. Advantageously, straight-tracking guidance of the at least one conveyor belt takes place. The pivoting roller advantageously compensates for at least temporary deviations of the belt travel from the straight-tracking guidance. Advantageously, the at least one conveyor belt is prevented from running laterally off at least one feed roller. The reaction time to a conveyor belt leaving its centered track guidance is advantageously reduced. The response advantageously takes place steplessly. The centering process of the at least one conveyor belt with respect to optimal tracking is advantageously accelerated. Advantageously, the service life of the at least one conveyor belt is increased. The maintenance complexity and service costs are advantageously reduced.

The pivot axis of the pivoting roller is advantageously situated along an axis of rotation of the pivoting roller, within a travel path of at least one conveyor belt, between a first end face and a second end face of the pivoting roller, preferably centered with respect to the travel path, more preferably centered between the first end face and the second end face of the pivoting roller. Advantageously, the at least one conveyor belt is guided back toward the center of the travel path, preferably toward the center of the roller, i.e., to its centered track, during the pivoting about the preferably centered pivot axis.

The at least one pivoting roller is configured so as to pivot automatically and/or pivots automatically about the pivot axis. In addition to the movement of the at least one conveyor belt, advantageously in particular no additional sensor system, for example sensors for detecting the edge of the conveyor belt, and/or a drive pivoting the at least one feed roller, for example a pneumatic cylinder, are required to correct and/or to ensure that the track of the at least one conveyor belt is maintained. Advantageously, an automatic reaction is carried out to a conveyor belt running off laterally and/or to external influences, which adversely affect the straight-tracking of the at least one conveyor belt. External influences include, in particular, irregular expansion of the at least one conveyor belt and/or the quality of the at least one conveyor belt and/or the homogeneity of the at least one conveyor belt and/or asymmetrical loading of the at least one conveyor belt, for example due to brushes or pressing means resting thereon, and/or the alignment of the feed rollers guiding the at least one conveyor belt, in particular deviations of the axis normal from a movement direction of the at least one conveyor belt and/or axial parallelism of the feed rollers. The at least one pivoting roller advantageously minimizes the adjustment effort during the initial adjustment. Advantageously, unnecessary subsequent corrections of the belt travel are dispensed with after initial tracking has been set.

Advantageously, automatic retensioning of the at least one conveyor belt takes place. Preferably, at least one further feed roller, preferably the respective further feed roller, can be displaced or is displaced with respect to the conveyor belt and/or can be fixed or is fixed in the displaced position by way of at least one tensioning device for changing the tension of the at least one conveyor belt. Advantageously, an additional tensioning device is dispensed with. The at least one tensioning device preferably comprises the at least one pivoting roller.

At least the at least one pivoting roller is advantageously configured as a cylindrical feed roller. Cylindrical rollers are advantageously easy and cost-effective to produce. Advantageously, the production costs of the feed rollers can be reduced through the use of the at least one cylindrical feed roller. Advantageously, the at least one conveyor belt is only exposed to minor stresses, for example since overstretching due to convex feed rollers can be reduced. The cylindrical configuration of at least one feed roller, preferably of at least the pivoting roller, more preferably of at least two feed rollers, more preferably of at least three feed rollers, advantageously reduces the wear of the at least one conveyor belt.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are illustrated in the drawings and will be described in greater detail below. The drawings show:

FIG. 1 an exemplary feeder for feeding sheets by way of a downstream transport unit configured as a suction belt table;

FIG. 2 a perspective side view of an exemplary transport unit comprising two conveyor belts revolving in each case over a pivoting roller;

FIG. 3 a schematic illustration of a guide, implemented by feed rollers, of the at least one revolving conveyor belt of the transport unit;

FIG. 4 a perspective view of a first preferred embodiment of a feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of a conveyor belt, a tensioning device comprising a spring system;

FIG. 5 a further view of the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of the conveyor belt, including the tensioning device, according to the preferred embodiment according to FIG. 4 ;

FIG. 6 the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of the conveyor belt, including the tensioning device according to the preferred embodiment according to FIG. 4 and FIG. 5 in a lateral partial section;

FIG. 7 an alternative preferred embodiment of the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of a conveyor belt in a perspective view, the tensioning device comprising at least one rocker arm;

FIG. 8 the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of a conveyor belt according to the preferred embodiment according to FIG. 7 in a lateral partial section;

FIG. 9 a further alternative preferred embodiment of the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of a conveyor belt in a perspective view, the tensioning device comprising at least one linear guide; and

FIG. 10 the feed roller configured as a pivoting roller and its tensioning roller arranged upstream in the movement direction of the conveyor belt according to the preferred embodiment according to FIG. 9 in a lateral partial section.

DETAILED DESCRIPTION

A sheet-processing machine is preferably configured as a printing press and/or a die-cutting machine. The sheet-processing machine preferably comprises at least one device, configured as a feeder 01, for feeding sheets, at least one processing mechanism and at least one delivery. The at least one processing mechanism is preferably a printing mechanism, preferably an offset printing mechanism, and/or a finish coating mechanism and/or an inkjet printing mechanism and/or a die-cutting mechanism. For example, the sheet-processing machine comprises at least one printing mechanism and additionally at least one finish coating mechanism. For example, in addition or as an alternative, the sheet-processing machine comprises at least one printing mechanism and additionally at least one die-cutting mechanism.

The sheet-processing machine comprises at least one transport unit 02 for transporting at least one sheet. The at least one transport unit 02 is arranged, for example, between the at least one feeder 01 and at least one first processing mechanism, i.e., preferably the first processing mechanism along a transport path of sheets. For example, in addition or as an alternative, at least one transport unit 02 is arranged between at least two consecutive processing mechanisms. For example, in addition or as an alternative, at least one transport unit 02 is arranged between a last processing mechanism, i.e., preferably the last processing mechanism along the transport path of sheets, and the at least one delivery, for example directly upstream from the at least one delivery. The at least one transport unit 02 is preferably configured as a belt table 02.

Preferably, at least one feed table including front lay marks, the infeed, and/or at least one processing mechanism of the sheet-processing machine are arranged downstream from the at least one transport unit 02, preferably the belt table 02. Preferably, the at least one transport unit 02, preferably the at least one belt table 02, feeds at least one sheet to the feed table including front lay marks and/or to the at least one processing mechanism of the sheet-processing machine. As an alternative, for example, the at least one delivery is arranged downstream from the at least one transport unit 02, and the at least one transport unit 02 then feeds the sheets to the at least one delivery.

The device for feeding sheets is preferably configured as a feeder 01 and preferably comprises a main pile carrier, in particular a pile board. Preferably, a pile composed of the sheets can be positioned and/or is positioned on the main pile carrier. The pile board is preferably attached to at least one transport means, for example to at least two transport means.

At the rear side and/or preferably at least at one side, for example at both sides, of the pile, blowers are provided, for example, for pre-loosening the sheets on the pile and/or for blowing air beneath the sheets during transport. To be able to form an air cushion carrying the sheets, metal side plates or guide elements that laterally delimit the pile can be, for example, additionally arranged next to the pile.

At least one feeder head 03 is preferably arranged in the region of the upper side of the pile. The feeder head 03 preferably comprises at least one separating sucker, for example at least two separating suckers, and at least one transport sucker, for example at least two transport suckers. The feeder head 03 is preferably arranged in the feeder 01 so as to be height-adjustable. In addition, the feeder head 03 is preferably displaceably mounted in or counter to a transport direction T to adapt to formats. The feeder head 03, in particular its at least one separating sucker, is preferably configured to cyclically separate the sheets from the pile. The at least one transport sucker preferably picks up the separated sheets. The at least one separating sucker preferably conveys the separated sheets in the transport direction T.

The transport direction T, provided in particular for transporting sheets, is a direction that preferably points from a first unit of the sheet-processing machine to a last unit of the sheet-processing machine, in particular from the at least one feeder 01 on the one hand, to a delivery or a substrate output device on the other hand, and/or that preferably points in a direction in which the at least one sheet is transported, in particular from a first contact with the sheet-processing machine to a last contact with the sheet-processing machine. The spatial area provided for transporting a sheet, which the at least one sheet, if present, at least temporarily occupies, is the transport path. The transport path is established by at least one transport means, in particular by at least one printing substrate guide element. Preferably, the at least one printing substrate guide element is in each case configured as at least one roller and/or at least one cylinder and/or at least one supporting surface and/or at least one other device for guiding the at least one sheet. The working width of the sheet-processing machine is preferably oriented orthogonal to the transverse direction T, in particular in a transverse direction. The working width of the sheet-processing machine is preferably at least 100 cm (one hundred centimeters), more preferably at least 150 cm, still more preferably at least 160 cm, still more preferably at least 200 cm, and still more preferably at least 250 cm.

At least one sensing device detecting the height of the pile is preferably arranged in the pile region. The at least one transport sucker preferably transports the sheets to the at least one transport unit 02, preferably to the at least one transport unit 02 configured as a belt table 02.

The at least one transport unit 02, preferably the at least one belt table 02, has a transport plane in which the sheets are transported by at least one revolving conveyor belt 04. The sheets are preferably transported lying flat and are arranged in the vertical direction above the at least one conveyor belt 04. As an alternative, for example, the sheets are preferably transported in a hanging state and are arranged in the vertical direction beneath the at least one conveyor belt 04. The at least one transport unit 02 preferably comprises at least one revolving conveyor belt, for example at least two or three revolving conveyor belts 04. The at least one conveyor belt 04 is guided over feed rollers 06; 07; 08; 09. A respective section of the at least one conveyor belt 04 is preferably guided over at least two feed rollers 06; 07 in the transport plane. The at least one transport unit 02 comprises at least one feed roller 06 configured as an infeed roller 06, and at least one feed roller 07 configured as a diverting roller 07, which define the transport plane of sheets. The at least one infeed roller 06 is preferably a first feed roller 06 of the at least one transport unit 02 along the transport path of sheets. The at least one diverting roller 07 is preferably a last feed roller 07 of the at least one transport unit 02 along the transport path of sheets.

In addition to the at least two feed rollers 06; 07 configured as an infeed roller 06 and as a diverting roller 07, at least one further feed roller, in particular, at least two further feed rollers 08; 09 are provided, guiding the at least one conveyor belt 04 outside, in particular beneath or above, the transport plane. The at least two further feed rollers 08; 09 of the transport unit 02, these preferably being at least one pivoting roller 08 and/or at least one tensioning roller 09, are preferably arranged outside the transport plane. The at least two, preferably at least three, more preferably at least four, for example two or three or four, further feed rollers 08; 09, over which the at least one conveyor belt 04 is guided, are preferably arranged outside, in particular beneath or above, the transport plane. The at least one further feed roller 08; 09 is thus preferably arranged outside, more preferably beneath or above, the transport plane. When sheets are transported lying flat, the at least one further feed roller 08; 09 is preferably arranged beneath the transport plane. When sheets are transported in a hanging state, the at least one further feed roller 08; 09 is preferably arranged above the transport plane.

At least one feed roller 08 of the further, preferably the at least two further, feed rollers 08; 09, is preferably configured as a pivoting roller 08 that pivots and/or can be pivoted about a pivot axis S. A feed roller 08 configured in this way preferably has a correcting belt guidance function, in particular when force and/or load changes occur in or on the at least one conveyor belt 04.

Preferably, at least one feed roller 09 of the further, preferably the at least two further, feed rollers 08; 09, is preferably configured as a tensioning roller 09. The at least one further feed roller 09 configured as a tensioning roller 09, which differs from the further feed roller 08 configured as a pivoting roller 08, is preferably arranged upstream from the pivoting roller 08 in the movement direction of the at least one conveyor belt 04. Preferably, the at least one tensioning roller 09 preferably comprises adjustable or fixed shaft mounts on both sides. The at least one tensioning roller 09 is preferably adjusted at its shaft mounts on both sides or is preferably fixed at its shaft mounts on both sides.

Preferably, the at least one transport unit 02, in particular the at least one transport unit 02 configured as a belt table 02, comprises the at least one, preferably revolving, conveyor belt 04. The at least one conveyor belt 04 is preferably configured to revolve around at least the at least one infeed roller 06 and the at least one diverting roller 07 and the at least one pivoting roller 08, preferably the at least one infeed roller 06 and the at least one diverting roller 07, and the at least one pivoting roller 08 and the at least one tensioning roller 09. The at least one conveyor belt 04 is preferably in contact with the at least one infeed roller 06 and the at least one diverting roller 07 and the at least one pivoting roller 08, preferably with the at least one infeed roller 06 and the at least one diverting roller 07, and the at least one pivoting roller 08 and the at least one tensioning roller 09. Instead of a single conveyor belt 04, two or more conveyor belts 04, which are spaced apart from each other and are guided over the at least two feed rollers 06; 07 configured as an infeed roller 06 and as a diverting roller 07 and at least one further feed roller, preferably at least two further feed rollers 08; 09, are provided, for example. Preferably, a respective pivoting roller 08, preferably a dedicated pivoting roller 08 and/or a pivoting roller pivoting independently from other pivoting rollers 08, is assigned to each of the at least two revolving conveyor belts 04. The at least one transport unit 02 preferably comprises at least two, for example two or three or four, revolving conveyor belts 04. The at least two revolving conveyor belts 04 are preferably guided over the feed rollers 06; 07; 08; 09. Preferably, each of the at least two revolving conveyor belts 04 is in each case guided over a pivoting roller 08. The at least two revolving conveyor belts 04 are preferably arranged parallel to one another and/or spaced apart from one another. Preferably, the at least one conveyor belt 04 is, preferably the conveyor belts 04 are, configured as a suction belt, preferably suction belts. The at least one conveyor belt 04 configured as a suction belt preferably has openings. The at least one suction belt is preferably supplied with suction air by suction boxes, which are, for example, integrated into the transport unit 02, preferably the belt table 02. Sheets to be transported are preferably held on the conveyor belt 04 configured as a suction belt due to the action of the suction air.

Preferably, a sheet flap, which is connected to a pivotably mounted shaft, is formed between the transporting suckers and the at least one conveyor belt 04 of the at least one transport unit 02, preferably belt table 02. The functional unit comprising the shaft and the sheet flap is also referred to as a flap shaft in technical jargon. The flap shaft preferably extends across the width of the pile. The sheet flap is pivoted for each sheet to be conveyed from a vertical position, in which the sheet flap forms a stop, into a horizontal position, in which the sheet flap forms a guide surface.

So-called timing rollers preferably cooperate with the at least one conveyor belt 04 of the at least one transport unit 02, preferably of the belt table 02. The timing rollers are preferably assigned to a pivotably mounted timing roller shaft. The timing roller shaft is preferably pivoted synchronized with the sequence of sheets, so that the timing rollers guide the front region of each sheet against the at least one conveyor belt 04.

At least one drive 16; 17; 18, which is preferably connected to a machine controller, is preferably provided for driving the components effectuating the sheet transport. Preferably, several individual drives 16; 17; 18, for example a first drive and/or a second drive 16 and/or a third drive 17 and/or a fourth drive and/or a fifth drive 18, are provided for driving the components effectuating the sheet transport, which preferably can be activated and/or are activated independently of one another. The individual drives 16; 17; 18, for example the first drive and/or the second drive 16 and/or the third drive 17 and/or the fourth drive and/or the fifth drive 18, are preferably connected to a controller, in particular a machine controller.

At least one feed roller 06; 07; 09 of the feed rollers 06; 07; 08; 09, which preferably differs from the pivoting roller 08, preferably comprises at least one drive, preferably the drive configured as the first drive, for driving the at least one conveyor belt 04. The at least one conveyor belt 04 is preferably driven by the at least one drive arranged at at least one feed roller 06; 07; 09 of the feed rollers 06; 07; 08; 09 which differs from the pivoting roller 08. The first drive is preferably configured as a motor, preferably an electric motor and/or a synchronous motor. Preferably, the at least one drive rotationally drives the at least one feed roller 06; 07; 09. The movement of the drive, in particular of the first drive, is preferably transferred to the at least one conveyor belt 04 by friction fit. Preferably, the at least one feed roller 06; 07; 09 comprising the first drive has a roughness depth Rz of at least 70, preferably at least 85, more preferably of at least 100, and/or of no more than 135, preferably of no more than 120, more preferably of no more than 115, for example of 108. Due to the surface roughness of the at least one feed roller 06; 07; 09 comprising the first drive, the driving torque is preferably optimally transferred to the at least one conveyor belt 04. The first drive is, for example, directly assigned to the axis of rotation R of the at least one feed roller 06; 07; 09 or is, for example, connected via at least one gear wheel pair or a belt drive, in particular a toothed belt drive, to the at least one feed roller 06, 07, 09 in terms of transmission. In the case of imbricated feeding of sheets by means of the at least one transport unit 02, for example, the at least one conveyor belt 04 preferably has a pulsating movement in its movement direction.

The movement direction of the at least one conveyor belt 04 is preferably the direction in which the at least one conveyor belt 04 moves in a revolving manner. The movement direction preferably changes in accordance with the guidance of the at least one conveyor belt 04. In the section of the transport plane, the movement direction of the at least one conveyor belt 04 is, for example, parallel to the transport direction T of the sheets. In the section of the at least one conveyor belt 04 outside the transport plane, in particular above or beneath, the movement direction preferably has at least one component that is directed counter to the transport direction T.

In a first, preferred, embodiment, the at least one feed roller 06 configured as an infeed roller 06, which is preferably arranged as the first feed roller 06 of the feed rollers 06; 07 along a transport path of sheets, comprises the at least one drive, preferably the drive configured as the first drive, more preferably the at least one drive for driving the at least one conveyor belt 04. The at least one conveyor belt 04 is preferably driven by the at least one drive arranged at the at least one infeed roller 06, which is arranged as the first feed roller 06 of the feed rollers 06; 07 along the transport path of sheets. This advantageously enables simple mechanical coupling to the at least one drive of the feeder 01 and/or to a single-turn shaft of the feeder 01. Preferably, a simple, preferably automatically arising, synchronization with the sequences of motions of the feeder 01 occurs. A section of the at least one conveyor belt 04 outside the transport plane is preferably pulled. Preferably, since a straight-tracking action of the pivoting roller 08 is dependent on the pulling force acting on the at least one conveyor belt 04 at the position of the pivoting roller 08, the drive being arranged at the at least one infeed roller 06 preferably supports the straight-tracking action of the pivoting roller 08. The at least one further feed roller 07 defining the transport plane, preferably the at least one diverting roller 07, preferably has a convex shape. Preferably, the at least one further feed roller 07 defining the transport plane, preferably the at least one diverting roller 07, can preferably be adjusted transversely to the direction of travel of the conveyor belt 04 and/or can be transferred into an oblique position and back transversely to the direction of travel of the conveyor belt 04. The embodiment of the at least one further feed roller 07 defining the transport plane, preferably of the at least one diverting roller 07, preferably enhances a straight-tracking guidance of the at least one conveyor belt 04 at the position of this feed roller 07 and/or increases the stability of the belt guidance.

In a second, alternative, embodiment, the at least one roller 07 configured as a diverting roller 07, which is arranged as the last feed roller 07 of the feed rollers 06; 07 along the transport path of sheets, comprises the at least one drive, preferably the drive configured as the first drive, more preferably the at least one drive for driving the at least one conveyor belt 04. The at least one conveyor belt 04 is preferably driven by the at least one drive arranged at the at least one diverting roller 07, which is arranged as the last feed roller 07 of the feed rollers 06; 07 along the transport path of sheets.

In a third, alternative embodiment, the at least one further feed roller 09 configured as a tensioning roller 09 comprises the at least one drive, preferably the drive configured as the first drive, more preferably the at least one drive for driving the at least one conveyor belt 04. The at least one conveyor belt 04 is preferably driven by the at least one drive arranged at the at least one further feed roller 09 configured as a tensioning roller 09.

In the second and in the third embodiment, the at least one conveyor belt 04 is consequently preferably configured as a pulling belt on the sheet-transporting side of the transport unit 02 preferably configured as a belt table 02. This has the advantage that the sheets located on the belt table 02 in the form of a sheet series can be transported more smoothly and uniformly. This preferably results in fewer disruptions. In the second and in the third embodiment, the section of the at least one conveyor belt 04 which is guided in the transport plane is advantageously pulled, whereby the belt tension is preferably reduced compared to a pushed belt guidance and/or the stresses of the at least one conveyor belt 04 are reduced compared to a pushed belt guidance.

For example, at least one feed roller 06; 07; 09 of the feed rollers 06; 07; 08; 09 which differs from the pivoting roller 08 has a convex or conical shape. A convex feed roller 06; 07; 08; 09 is also referred to as a crowned roller and preferably has a cross-sectional thickening deviating from the cylindrical shape. The at least one convex feed roller 06; 07; 08; 09 preferably has a minimum cross-section at at least one end face. The cross-sectional thickening preferably occurs in the travel path of a guided object, preferably the at least one conveyor belt 04, preferably centered in its travel path, and more preferably centered between the end faces. For example, the at least one convex feed roller 06; 07; 08; 09 has a convex, also referred to as crowned, shape. As an alternative, for example, the at least one convex feed roller 06; 07; 08; 09 has a trapezoidal shape. A conical feed roller 06; 07; 08; 09 preferably has a conical cross-section change of the outer cylindrical surface. For example, a conical feed roller 06; 07; 08; 09 has a maximum cross-section at one end face, and a minimum cross-section at the opposite end face. As an alternative, for example, a conical feed roller 06; 07; 08; 09, which then is also referred to as biconical, for example, has the maximum cross-section at a position between the two end faces, wherein the cross-section conically decreases toward the two end faces. Combinations are also possible, for example, wherein at least one feed roller 06; 07; 09 has a first convex or conical embodiment, and at least one second feed roller 06; 07; 09 has a convex or conical embodiment different therefrom.

In a preferred embodiment, the feed roller 06; 07; 09 comprising the at least one drive, preferably the drive configured as the first drive, which is preferably referred to as a drive roller, has a cylindrical shape. The feed roller 06; 07; 09 comprising the drive for driving the at least one conveyor belt 04 preferably has a cylindrical shape. Due to the cylindrical configuration of the feed roller 06; 07; 09 acting as a drive roller, the wear of the at least one guided conveyor belt 04 is preferably reduced compared to a convex or conical configuration. A cylindrical feed roller 06; 07; 08; 09 preferably has a uniform cross-section along its axis of rotation R. Cylindrical rollers shall preferably also be understood to mean rollers that have a cylindrical shape and are rounded, stepped, chamfered or offset toward their end faces.

In an alternative embodiment, the feed roller 06; 07; 09 comprising the at least one drive, preferably the drive configured as the first drive, has the convex or conical shape. As a result, the feed roller 06, 07, 09 configured with the convex or conical shape and acting as a drive roller additionally preferably assumes a centering function, in addition to the driving function.

In addition to the first drive assigned to a feed roller 06, 07; 09, a second drive 16 is provided, for example, which is assigned to the shaft supporting the sheet flap. The second drive 16 is configured, for example, to jointly drive the timing roller shaft and the shaft connected to the sheet flap. The timing roller shaft and/or the shaft connected to the sheet flap are preferably connected to the second drive 16 by way of a gear mechanism. In addition, or as an alternative, for example, a third drive 17 is assigned to the main pile carrier for the vertical displacement thereof. If a non-stop mechanism is provided, the main pile carrier preferably cooperates with an auxiliary pile carrier during pile changing, which is preferably configured as a rake or roller rack and to which a fourth drive is preferably assigned for the vertical displacement thereof. A fifth drive 18 is provided, for example additionally or alternatively, for driving the feeder head 03 and/or the transporting sucker.

For example, at least one sheet arrival sensor is, for example two sheet arrival sensors are, configured to detect the arrival of the sheets, the sheet arrival sensor preferably being arranged at the end of the at least one transport unit 02 preferably configured as a belt table 02. The at least one sheet arrival sensor can preferably be used to detect the position of the sheets at a particular point in time prior to the sheets entering the processing mechanism. The at least one sheet arrival sensor preferably generates first signals representing the arrival of the sheets for a sequence of sheets. A clock generator, which preferably generates second signals representing the angular position of the at least one processing mechanism, is configured to detect the angular position of the at least one processing mechanism. It is preferably only possible to feed sheets to the at least one processing mechanism when the at least one processing mechanism, in particular its sheet-guiding cylinder, is in a particular angular position. To achieve this, the individual drives 16; 17; 18, for example the first drive and/or the second drive 16 and/or the third drive 17 and/or the fourth drive and/or the fifth drive 18, must be accordingly activated. The drives 16; 17; 18, for example the first drive and/or the second drive 16 and/or the third drive 17 and/or the fourth drive and/or the fifth drive 18, as well as the clock generator and the sheet arrival sensor are preferably connected to a controller, in particular a machine controller.

The controller preferably controls the first drive of the relevant feed roller 06; 07; 09 as a function of the signals of the clock generator, in particular the second signals. In other words, the movement of the conveyor belt or belts 04 of the transport unit 02, preferably of the belt table 02, preferably exclusively follows the movement of the at least one processing mechanism. In contrast to the first drive, the second drive 16 is preferably not only controlled by the controller according to the second signals of the clock generator, but additionally also according to the first signals of the sheet arrival sensor. Respective clock-based speed profiles are preferably entered into the controller for controlling the first and/or second drives 16. The speed profiles, for example, have a discontinuous speed curve. The controller preferably ascertains the phase positions of the first signals in relation to the phase positions of the second signals and controls the second drive 16 as a function of the ascertained phase positions of the first signals in relation to the phase positions of the second signals. In this way, the occurrence of sheets arriving too early (early sheets) or the occurrence of sheets arriving too late (late sheets) is inferred, and appropriate counter measures are taken.

The controller is, in particular, configured to control the second drive 16 so as to shift, as a function of the phase positions of the first signals in relation to the phase positions of the second signals, the phase positions of the speed profile of the second drive 16 in a leading or trailing manner with respect to the phase positions of the speed profile of the first drive, or to activate the second drive 16 using a speed profile that has an increased or a decreased average speed. If, for example, a late sheet is determined as a result of the ascertainment of the phase positions, an increased speed of the fifth drive 18 of the feeder head 03 and/or of the transporting sucker and an increased speed of the second drive 16 at the sheet flap with respect to the conveyor belt 04 are used to induce the leading sheet edge of succeeding sheets to preferably arrive earlier at the processing mechanism. The imbrication length between the sheets is preferably thereby reduced. The controller responds to an early sheet in a corresponding manner, for example, with the difference that the speed of the fifth drive 18 and of the second drive 16 is reduced, and the imbrication length, that is, the distance between the leading edges of the sheets, is increased. It is also possible to provide multiple sheet arrival sensors monitoring the sheets.

At least one feed roller 06; 07; 08; 09 of the feed rollers 06; 07; 08; 09, preferably each feed roller 06; 07; 08; 09, in each case has a first end face and a second end face and at least one outer cylindrical surface.

The at least one feed roller 06; 07; 08; 09, preferably each feed roller 06; 07; 08; 09, has an axis of rotation R. The axis of rotation R of the at least one feed roller 06; 07; 08; 09 is directed from the first end face to the second end face. The at least one feed roller 06; 07; 08; 09, preferably each feed roller 06; 07; 08; 09, is preferably configured so as to rotate and/or be rotatable about its axis of rotation R. The axis of rotation R of the at least one feed roller 06; 07; 08; 09 is preferably directed perpendicularly to the transverse direction T, preferably in the transverse direction and/or in the direction of the working width. For example, a normal of the axis of rotation R of at least one feed roller 06; 07; 08; 09, preferably of all feed rollers 06; 07; 08; 09, preferably points in a direction orthogonal to the axis of rotation R, preferably in or counter to the movement direction of the at least one conveyor belt 04, more preferably in or counter to the transport direction T or in or counter to a vertical direction. Above and below, an axis of rotation R of a body denotes the straight line about which this body can be rotated, without the view of the body changing. The axis of rotation R is thus preferably also an axis of symmetry of the body. During a rotation about the axis of rotation R, the individual points of the body preferably move on circles in planes perpendicular to the respective axis of rotation.

The axes of rotation R of at least two feed rollers 06; 07; 08; 09, preferably of at least three feed rollers 06; 07; 08; 09, more preferably of all feed rollers 06; 07; 08; 09, are preferably situated parallel to one another. As a result, the at least one conveyor belt 04 is preferably guided in a straight-tracking manner over the at least two feed rollers 06; 07; 08; 09, preferably over the at least three feed rollers 06; 07; 08; 09, more preferably over all feed rollers 06; 07; 08; 09.

The at least one feed roller 06; 07; 08; 09, preferably at least the at least one pivoting roller 08, more preferably at least two feed rollers 06; 07; 08; 09, more preferably at least three feed rollers 06; 07; 08; 09, more preferably each feed roller 06; 07; 08; 09 of the at least one transport unit 02, preferably has a cylindrical shape. The at least one pivoting roller 08 preferably has a cylindrical shape. Preferably, at least the at least one pivoting roller 08 and the feed roller 06; 07; 09 comprising the drive configured as the first drive have a cylindrical shape. Preferably, the at least one infeed roller 06 and the at least one pivoting roller 08 and the at least one tensioning roller 09 have a cylindrical shape. More preferably, the at least one infeed roller 06 and/or the at least one diverting roller 07 and/or the at least one pivoting roller 08 and/or the at least one tensioning roller 09 have a cylindrical shape. The cylindrical configuration preferably facilitates the production of these feed rollers 06; 07; 08; 09. In a preferred embodiment, all feed rollers 06; 07; 08; 09 of the at least one transport unit 02 have a cylindrical shape. Preferably, the cylindrical configuration of the at least one feed roller 06; 07; 08; 09 reduces the wear of the at least one conveyor belt 04, preferably since the expansion and contraction of the conveyor belt 04, and the lateral relative movement associated therewith, such as occurs, for example, with convex feed rollers, are minimized.

For example, in addition or as an alternative, at least one feed roller 06; 07; 09 of the feed rollers 06; 07; 08; 09 which differs from the pivoting roller 08 has a convex or conical shape. For example, the at least one diverting roller 07 has a convex or conical shape, preferably in particular when the at least one infeed roller 06 comprises the first drive. For example, as an alternative, the convex or conical feed roller 06; 07; 09 comprises the at least one drive.

The at least one pivoting roller 08 is configured to pivot automatically about the pivot axis S. The at least one pivoting roller 08 preferably automatically corrects belt misalignment. Above and below, automatic pivoting of the at least one pivoting roller 08 about its pivot axis S preferably denotes pivoting that is, preferably exclusively, caused by the influence of the at least one conveyor belt 04, preferably its movement in the movement direction while revolving. The at least one pivoting roller 08 preferably does not comprise an additional drive which pivots the pivoting roller 08 about its pivot axis S, in particular no additional drive in addition to a movement of the at least one conveyor belt 04 in its movement direction. The belt travel of the at least one conveyor belt 04 is preferably purely mechanically regulated. Preferably, no sensors or controllers are required for regulating belt travel. The at least one pivoting roller 08 is preferably configured to pivot automatically from a first position pivoted in a mathematically positive sense of rotation into a position in which the axis of rotation R of the pivoting roller 08 is situated parallel to at least one axis of rotation R of at least one of the further feed rollers 06; 07; 09, and/or in the opposite direction. The at least one pivoting roller 08 is preferably configured to pivot automatically from a second position pivoted in a mathematically negative sense of rotation into a position in which the axis of rotation R of the pivoting roller 08 is situated parallel to at least one axis of rotation R of at least one of the further feed rollers 06; 07; 09, and/or in the opposite direction. The at least one pivoting roller 08 is preferably configured to pivot automatically between the first pivoted position and the second pivoted position and the position in which the axis of rotation R of the pivoting roller 08 is situated parallel to at least one axis of rotation R of at least one of the further feed rollers 06; 07; 09.

The at least one pivoting roller 08 preferably allows the belt guidance to be easily adjusted. The at least one pivoting roller 08 preferably allows the system, in particular the transport unit 02, to react rapidly to disturbing influences and/or changes at the at least one conveyor belt 04. Self-regulating and/or constantly centered travel of the at least one conveyor belt 04 is preferably achieved with preferably little adjustment effort. The reaction time to a conveyor belt 04 veering off track is preferably rapid and/or takes place steplessly. Preferably, a conveyor belt 04 veering off track is returned to its track. The sheet feeding is preferably stabilized.

A centered guidance of the at least one conveyor belt 04 is preferably its straight-tracking guidance on the at least one feed roller 06; 07; 08; 09, in particular without lateral run-off.

The at least one pivoting roller 08, preferably the respective one pivoting roller 08 per conveyor belt 04, has the pivot axis S. Above and below, a pivot axis S of a body preferably denotes the axis about which this body can be pivoted and/or is pivoted. In the process, the view of the body preferably changes. During a pivoting movement about the pivot axis S, the individual points of the body preferably move on circles in planes perpendicular to the respective pivot axis S. In contrast to a rotation, preferably no full revolution of the body, i.e., by 360°, is achieved during pivoting. For example, a maximum deflection of the body during a pivoting movement about its pivot axis S is 180°. Both the starting position and the at least one pivoted position of the body, preferably of the at least one pivoting roller 08, are preferably arranged within a plane perpendicular to the pivot axis S, preferably the pivot axis S of the pivoting roller 08. The pivot axis S of the at least one pivoting roller 08 is an axis normal of the axis of rotation R of the pivoting roller 08.

A vector that is situated perpendicularly on a plane and/or a surface and/or an axis and/or a direction is its normal vector. Above and below, the vector which is situated perpendicularly on an axis is preferably referred to as its axis normal.

The pivot axis S of the at least one pivoting roller 08 is preferably situated along the axis of rotation R of the pivoting roller 08 within a travel path, preferably centered with respect to the travel path, of the at least one conveyor belt 04 between the first end face and the second end face of the pivoting roller 08. The pivot axis S of the at least one pivoting roller 08 is more preferably situated along the axis of rotation R of the pivoting roller 08 centered between the first end face and the second end face of the pivoting roller 08. The at least one pivoting roller 08 is preferably configured so as to be pivotable and/or pivot symmetrically about the pivot axis S. The pivot axis S is preferably situated at the position of the center of mass of the pivoting roller 08. In a two-dimensional projection of the pivoting roller 08 parallel to the axis of rotation R of the pivoting roller 08, the pivot axis S is preferably situated at the position of the center of area, i.e., preferably centered along the axis of rotation R, in particular centered between the first end face and the second end face of the pivoting roller 08.

The transport direction T of sheets and a direction perpendicular thereto, wherein the perpendicular direction is preferably situated perpendicularly on the transport direction T and on the direction of the working width, preferably span a projection plane. In the projection plane, a first stretch is preferably arranged between the axis of rotation R of the at least one infeed roller 06 and the axis of rotation R of the at least one diverting roller 07. In the projection plane, a second stretch is preferably arranged between the axis of rotation R of the at least one infeed roller 06 and the axis of rotation R of the pivoting roller 08. In the projection plane, the first stretch between the axis of rotation R of the at least one infeed roller 06 and the axis of rotation R of the at least one diverting roller 07 preferably has an opening angle with respect to the second stretch between the axis of rotation R of the at least one infeed roller 06 and the axis of rotation R of the pivoting roller 08. The opening angle is preferably acute. The opening angle is preferably no more than 45° (forty-five degrees), preferably no more than 40° (forty degrees), more preferably no more than 30° (thirty degrees), more preferably no more than 25° (twenty-five degrees), more preferably no more than 20° (twenty degrees), and more preferably no more than 15° (fifteen degrees). The opening angle is preferably the angle between the first stretch and the second stretch during a rotation from the first stretch to the second stretch with a mathematically negative sense of rotation, i.e., preferably a clockwise rotation.

The mathematically negative sense of rotation is the direction of rotation of a circular area that rotates about an axis extending perpendicularly through its center and is viewed in the direction of the axis of rotation, wherein points on the area located above the center describe a movement extending to the right. The mathematically negative sense of rotation is preferably the direction of rotation to the right, or clockwise. The mathematically positive sense of rotation is the direction of rotation of a circular area that rotates about an axis extending perpendicularly through its center and is viewed in the direction of the axis of rotation, wherein points on the area located above the center describe a movement extending to the left. The mathematically positive sense of rotation is preferably the direction of rotation to the left, or counterclockwise.

The pivot axis S preferably intersects the transport plane. Preferably, the pivot axis S has an opening angle with respect to the transport plane, preferably during a rotation from the transport plane onto the pivot axis S with a mathematically negative sense of rotation, i.e., preferably a clockwise rotation. The opening angle of the pivot axis S of the pivoting roller 08 with respect to the transport plane is preferably at least 40° (forty degrees), preferably at least 50° (fifty degrees), more preferably at least 60° (sixty degrees), more preferably at least 70° (seventy degrees), for example at least 75° (seventy-five degrees) and/or no more than 140° (one hundred and forty degrees), preferably no more than 130° (one hundred and thirty degrees), more preferably no more than 120° (one hundred and twenty degrees), more preferably no more than 110° (one hundred and ten degrees), for example no more than 105° (one hundred and five degrees).

The pivot axis S preferably has an angle with respect to the movement direction of the at least one conveyor belt 04 entering the pivoting roller 08. The at least one entering conveyor belt 04 is preferably the section of the at least one conveyor belt 04 which is arranged upstream from the pivoting roller 08, in particular arranged directly upstream thereof, in the movement direction of the at least one conveyor belt 04. Proceeding from the movement direction, pivoted with respect to the pivot axis S in a mathematically negative sense of rotation, i.e., preferably clockwise, the pivot axis S of the pivoting roller 08 preferably has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees), preferably no more than 15° (fifteen degrees), more preferably no more than 10° (ten degrees), more preferably no more than 5° (five degrees), with respect to the movement direction of the at least one conveyor belt 04 entering the pivoting roller 08. As an alternative or in addition, proceeding from the movement direction, pivoted with respect to the pivot axis S in a mathematically positive sense of rotation, i.e., preferably counterclockwise, the pivot axis S of the pivoting roller 08 preferably has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees), preferably no more than 15° (fifteen degrees), more preferably no more than 10° (ten degrees), more preferably no more than 5° (five degrees), with respect to the movement direction of the at least one conveyor belt 04 entering the pivoting roller 08. More preferably, the angle is 0° (zero degrees). More preferably, the pivot axis S of the pivoting roller 08 is situated parallel to the movement direction of the at least one entering conveyor belt 04. The at least one conveyor belt 04 thus preferably enters the pivoting roller 08 parallel to the pivot axis S of the pivoting roller 08.

The pivot axis S preferably has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees), preferably no more than 15° (fifteen degrees), more preferably no more than 10° (ten degrees), more preferably no more than 5° (five degrees), with respect to a straight line that makes contact with the pivoting roller 08 at a position of the outer cylindrical surface at which the at least one conveyor belt 04 for the first time makes contact with the pivoting roller 08, and which makes contact with the further feed roller 09 arranged upstream from the pivoting roller 08, in particular configured as a tensioning roller 09, or a pressing element arranged directly upstream from the pivoting roller 08, at a position of its outer cylindrical surface at which the at least one conveyor belt 04 is in contact for the last time with the tensioning roller 09 or the pressing element. More preferably, the pivot axis S is parallel to this straight line.

Preferably, the at least one pivoting roller 08, preferably the respective one pivoting roller 08 per conveyor belt 04, is mounted in at least one carrier, in particular a carrier configured as a fork carrier 21, preferably at its end faces. The at least one carrier preferably includes the swivel axis S. The at least one pivoting roller 08, together with the at least one carrier, is preferably arranged so as to pivot and/or be pivotable about the pivot axis S. The at least one pivoting roller 08, preferably the at least one carrier together with the pivoting roller 08, preferably has a low mass moment of inertia. Preferably, the at least one pivoting roller 08, preferably the at least one carrier together with the pivoting roller 08, is mounted without clearance and/or smoothly about the pivot axis S. In this way, even a minor deviation of the at least one conveyor belt 04 from its centered track guidance can preferably be compensated for and/or is compensated for.

The at least one conveyor belt 04 preferably has a wrap angle when wrapped around the respective feed roller 06; 07; 08; 09. The wrap angle preferably indicates the contact region between the at least one conveyor belt 04 and the respective feed roller 06; 07; 08; 09. The at least one conveyor belt 04 preferably wraps around the pivoting roller 08 at the wrap angle. Preferably, the wrap angle of the at least one conveyor belt 04 around the pivoting roller 08 is no more than 120°, preferably no more than 105°, more preferably no more than 95°, and/or at least 60°, preferably at least 75°, more preferably at least 85°. More preferably, this wrap angle is 90°. Preferably, the wrap angle of the at least one conveyor belt 04 around the tensioning roller 09, which is arranged upstream from the pivoting roller 08, is no more than 120°, preferably no more than 105°, more preferably no more than 95° and/or at least 60°, preferably at least 75°, more preferably at least 85°. More preferably, this wrap angle is 90°.

For example, at least one feed roller 06; 07; 08; 09, preferably at least one of the further feed rollers 08; 09, more preferably at least the at least one pivoting roller 08, comprises grooves and/or microgrooves in the direction of rotation of the feed roller 06; 07; 08; 09. Preferably, so as to prevent the at least one conveyor belt 04 from running off the respective feed roller 06; 07; 08; 09, the grooves and/or microgrooves preferably extend symmetrically from the center of the feed roller 06; 07; 08; 09, preferably along the axis of rotation R, to its end faces. Angular momentum, also referred to as spin, preferably acts toward the center of the feed roller 06; 07; 08; 09, i.e., toward the point along the axis of rotation R after half the roller body.

Preferably, at least one tensioning device for tensioning the at least one conveyor belt 04 is provided. The at least one tensioning device for tensioning the at least one conveyor belt 04 is preferably provided outside, in particular beneath or above, the transport plane. The at least one tensioning device preferably comprises the at least one pivoting roller 08. The at least one tensioning device preferably comprises the at least one pivoting roller 08 and the at least one tensioning roller 09. Preferably, the respective further feed roller 08; 09 can be displaced or is displaced with respect to the at least one conveyor belt 04, preferably with respect to the conveyor belt 04, and/or can be fixed or is fixed in the displaced position, by way of the at least one tensioning device to change the tension of the at least one conveyor belt 04. The at least one preferably cylindrical further feed roller 09 configured as a tensioning roller 09, which is preferably configured as an entering roller of the tensioning device, is preferably arranged upstream from the pivoting roller 08, preferably without further interposed feed rollers 08; 09. The pivoting roller 08 is preferably configured as an exiting roller, in particular diverting roller, of the tensioning device. The at least one conveyor belt 04 is preferably tensioned by the at least one tensioning device for tensioning the at least one conveyor belt 04. Preferably, the at least one tensioning device is configured so as to pneumatically adjust and/or control the tensioning force against the at least one conveyor belt 04, preferably by means of at least one pneumatic cylinder. The tensioning force of the at least one tensioning device against the at least one conveyor belt 04 is preferably pneumatically adjusted and/or controlled. The tension of the at least one conveyor belt 04 is preferably adjusted by the relative distance of the at least one pivoting roller 08 and the at least one tensioning roller 09 with respect to each other.

The at least one tensioning device, for example, comprises at least one energy accumulator, in particular a spring system 24, its spring force preferably being adjustable and/or being adjusted. Preferably, the at least one energy accumulator preferably resiliently tensions one of the further feed rollers 08; 09 against the at least one conveyor belt 04. Preferably in addition or as an alternative to the spring system 24, the at least one energy accumulator is configured as a tensioning system comprising at least one tensioning means. The at least one tensioning means is preferably at least one rocker arm 22. Preferably in addition or as an alternative, the at least one tensioning system comprises at least one linear guide 23, preferably at least one parallel guide 23, more preferably at least one linear guide 23 for guiding at least one bearing element, and more preferably at least one linear guide 23 for guiding at least one fixation element. Preferably, the at least one tensioning means is the at least one bearing element, preferably the at least one fixation element. Preferably, the at least one feed roller 08; 09, preferably the at least one tensioning roller 09, is arranged on, preferably attached to, the at least one linear guide 23 by means of the at least one bearing element, preferably by means of the at least one fixation element. The at least one tensioning device thus preferably comprises at least one spring system 24 or at least one rocker arm 22 or at least one linear guide 23. The at least one conveyor belt 04 is preferably tensioned by the at least one spring system 24 or by the at least one rocker arm 22 or by the position of the at least one further feed roller 08; 09, preferably the at least one tensioning roller 09, along the at least one linear guide 23. For example, the energy accumulator, in particular its at least one spring or its at least one tensioning means, is pneumatically controlled and/or controllable. The tensioning force of the energy accumulator against the at least one conveyor belt 04 is preferably pneumatically adjusted, preferably by means of at least one pneumatic cylinder. Preferably, force regulation is present here. Advantageously, the tension of the at least one conveyor belt 04 is adjusted to be uniform, in particular also during operation. As a result, the wear of the at least one conveyor belt 04 is advantageously reduced.

In a preferred first embodiment, the at least one energy accumulator is configured so as to act on the at least one pivoting roller 08. The at least one energy accumulator preferably tensions the at least one pivoting roller 08 against the at least one conveyor belt 04. For example, the energy accumulator is configured as a spring system 24. The spring system 24 preferably acts on the at least one carrier of the at least one pivoting roller 08, which preferably transfers the tensioning force onto the at least one pivoting roller 08. The at least one carrier preferably comprises at least one bearing for this purpose, about which the carrier is pivotably mounted.

In a preferred second embodiment, the at least one energy accumulator is configured so as to act on the at least one tensioning roller 09. The at least one energy accumulator preferably tensions the at least one tensioning roller 09 against the at least one conveyor belt 04. The at least one tensioning roller 09 is preferably mounted in at least one rocker arm 22 acting as a tensioning means. The at least one rocker arm 22 preferably tensions the at least one tensioning roller 09 pneumatically against the at least one conveyor belt 04.

In a preferred third embodiment, the at least one energy accumulator is configured so as to act on the at least one tensioning roller 09. The at least one energy accumulator preferably tensions the at least one tensioning roller 09 against the at least one conveyor belt 04. For example, the at least one further feed roller 08; 09, preferably the at least one tensioning roller 09, comprises the at least one linear guide 23, preferably parallel guide 23. The at least one tensioning roller 09 preferably comprises the at least one linear guide 23. Preferably, the position of the at least one further feed roller 08; 09, preferably of the at least one tensioning roller 09, along the linear guide 23 is adjustable, preferably pneumatically adjustable. The position of the at least one further feed roller 08; 09, preferably of the at least one tensioning roller 09, along the linear guide 23 can preferably be fixed by means of the at least one tensioning means configured as a bearing element, preferably by means of the at least one tensioning means configured as a fixation element. Preferably, the at least one bearing element, preferably the at least one fixation element, is adjustable along the at least one linear guide 23. Preferably, the at least one bearing element, preferably the at least one fixation element, can be fixed and released at its position along the at least one linear guide 23, in particular in a position in which the at least one conveyor belt 04 is tensioned. Preferably, the at least one tensioning roller 09, due to its position along the at least one linear guide 23, is preferably pneumatically tensioned against the at least one conveyor belt 04.

It is possible for different embodiments of the tensioning device to be combined with one another. For example, at least one energy accumulator, preferably at least one tensioning system or spring system 24, can be provided in each case both at the pivoting roller 08 and at the tensioning roller 09. Or, for example, at least two different tensioning means are provided at the at least one tensioning roller 09. Each such combination is then preferably assigned to at least two of the embodiments of tensioning device.

The at least one conveyor belt 04 of the sheet-processing machine is preferably guided in a straight-tracking manner. The at least one conveyor belt 04 is preferably guided around the at least one feed roller 06 configured as an infeed roller 06, and the at least one feed roller 07 configured as a diverting roller 07. The at least one infeed roller 06 and the at least one diverting roller 07 define the transport plane of sheets. The at least one conveyor belt 04 is preferably guided around the at least two further feed rollers 08; 09 of the transport unit 02, preferably around the at least one pivoting roller 08 and/or around the at least one tensioning roller 09, outside the transport plane. The at least one conveyor belt 04 is preferably guided over the preferably cylindrical pivoting roller 08. The at least one further feed roller 08 configured as a pivoting roller 08 pivots about the pivot axis S. The pivot axis S of the pivoting roller 08 is an axis normal of the axis of rotation R of the pivoting roller 08. More preferably, the at least one conveyor belt 04 is guided over the at least one preferably cylindrical infeed roller 06 and the at least one preferably cylindrical diverting roller 07 and the at least one preferably cylindrical pivoting roller 08 and the at least one preferably cylindrical tensioning roller 09. For example, as an alternative to the cylindrical configuration of all feed rollers 06; 07; 08; 09, the at least one conveyor belt 04 is guided over at least one convex or conical feed roller 06; 07; 09 of the feed rollers 06; 07; 08; 09, the feed roller 06; 07; 09 differing from the pivoting roller 08, for example the convex or conical diverting roller 07. For example, the at least one conveyor belt 04 is guided over the at least one cylindrical infeed roller 06 and the at least one convex or conical diverting roller 07 and the at least one cylindrical pivoting roller 08 and the at least one cylindrical tensioning roller 09.

The at least one pivoting roller 08 preferably pivots about the pivot axis S situated along the axis of rotation R of the pivoting roller 08 within the travel path of the at least one conveyor belt 04 between the first end face and the second end face of the pivoting roller 08, preferably centered with respect to the travel path. More preferably, the pivot axis 08 pivots about the pivot axis S situated along the axis of rotation R of the pivoting roller 08 centered between the first end face and the second end face of the pivoting roller 08.

The at least one pivoting roller 08 pivots automatically about the pivot axis S, i.e., preferably without a further drive, in particular in addition to the movement of the at least one conveyor belt 04. The automatic pivoting preferably describes that the at least one pivoting roller 08 is preferably exclusively pivoted about the pivot axis S by the belt tension of the at least one conveyor belt 04, in particular while it is moving the movement direction.

In the case of a convex and/or conical roller, the at least one conveyor belt 04 preferably runs on the side having maximum expansion. In the case of cylindrical rollers, the at least one conveyor belt 04 preferably runs on the side of the least expansion, i.e., the side where it first meets the roller. In particular in the case of cylindrical feed rollers 06; 07; 08; 09, the at least one conveyor belt 04 thus leaves its centered track in the case of irregular expansion, and runs to the side, i.e., in the direction of an end face of the respective feed roller 06; 07; 08; 09.

The at least one pivoting roller 08, preferably the respective one pivoting roller 08 per conveyor belt 04, preferably generates an effect that is counter to the lateral run-off of the at least one conveyor belt 04 off the at least one feed roller 06; 07; 08; 09, preferably off the pivoting roller 08. The at least one conveyor belt 04 is preferably returned to the centered, i.e., straight-tracking, preferably symmetrical position. The centered position is preferably the position that corresponds to the optimal travel path of the conveyor belt 04, preferably its track. The at least one conveyor belt 04 is preferably guided toward the center of the travel path of the conveyor belt 04, preferably toward the center between the first end face and the second end face of the pivoting roller 08, preferably as a result of the pivoting of the at least one pivoting roller 08. The travel path of the conveyor belt 04 preferably runs centered between the first end face and the second end face of the at least one pivoting roller 08. Preferably, the rotation of the at least one pivoting roller 08 about its axis of rotation R and/or the pivoting of the at least one pivoting roller 08 about its pivot axis S are preferably exclusively driven by the movement of the at least one conveyor belt 04.

External influences on the at least one conveyor belt 04 include, in particular, irregular expansion of the at least one conveyor belt 04 and/or the quality of the at least one conveyor belt 04 and/or the homogeneity of the at least one conveyor belt 04 and/or asymmetrical loading of the at least one conveyor belt 04, for example due to brushes or pressing means resting thereon, and/or the alignment of the feed rollers 06; 07; 08; 09 guiding the at least one conveyor belt 04, in particular deviations of the axis normal from a movement direction of the at least one conveyor belt 04 and/or axial parallelism of the feed rollers 06; 07; 08; 09. For example, a sheet resting on the at least one conveyor belt 04 exerts external influence on the conveyor belt 04. For example, when at least two conveyor belts 04 arranged next to one another in the axial direction transport the sheet, the sheet, whose center of mass is located closer to a first of the at least two conveyor belts 04 than a second conveyor belt 04, pulls at least one of the conveyor belts 04 out of its straight-tracking guidance.

For example, due to external influences, the at least one conveyor belt 04 runs along the outer cylindrical surface laterally to the first end face of the pivoting roller 08, for example in a top view to the left end face. The region of the outer cylindrical surface of the pivoting roller 08 facing the first end face, i.e., for example, the left region of the pivoting roller 08, is thus subjected to greater loading, due to the tensioned at least one conveyor belt 04, than the region of the outer cylindrical surface facing the second end face, i.e., the right region in the example. Due to the greater loading of the outer cylindrical surface in the region facing the first end face, i.e., the left region in the example, the pivoting roller 08 pivots about the pivot axis S so that the region of the outer cylindrical surface facing the second end face, i.e., the right region, for example, first makes contact with the at least one conveyor belt 04. The pivoting roller 08 thus preferably pivots counter to the movement direction of the at least one conveyor belt 04 exiting the pivoting roller 08. The at least one conveyor belt 04 preferably runs on the side of the pivoting roller 08 with which the at least one conveyor belt 04 makes contact first. In the example, the at least one conveyor belt 04 thus runs to the region of the outer cylindrical surface facing the second end face, i.e., to the right, for example. As a result, the at least one conveyor belt 04 is preferably returned from its arrangement in the region of the outer cylindrical surface facing the first end face to a centered arrangement. Preferably, the pivoting roller 08 pivots counter to its preceding pivoting movement, the further the at least one conveyor belt 04 runs toward the center, and the more evenly the pivoting roller 08 is loaded in, for example, the left and right regions of the outer cylindrical surface, i.e., preferably the more symmetrically it is loaded.

If the at least one conveyor belt 04, due to the external influences, runs to the second end face, pivoting of the pivoting roller 08 follows so that the at least one conveyor belt 04 makes contact first with the region of the outer cylindrical surface facing the first end face.

Although the disclosure herein has been described in language specific to examples of structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described in the examples. Rather, the specific features and acts are disclosed merely as example forms of implementing the claims. 

1-63. (canceled)
 64. A sheet-processing machine, comprising at least one transport unit (02) for transporting sheets, the at least one transport unit (02) comprising at least one feed roller (06) configured as an infeed roller (06) and at least one feed roller (07) configured as a diverting roller (07), which define a transport plane of sheets, at least two further feed rollers (08; 09) of the transport unit (02) being arranged outside the transport plane, at least one feed roller (08) of the at least two further feed rollers (08; 09) being configured as a pivoting roller (08) that pivots and/or can be pivoted about a pivot axis (S), and the pivot axis (S) of the pivoting roller (08) being an axis normal of an axis of rotation (R) of the pivoting roller (08), characterized in that the at least one pivoting roller (08) is configured so as to automatically pivot about the pivot axis (S).
 65. The sheet-processing machine according to claim 64, characterized in that the pivot axis (S) of the pivoting roller (08) is situated along an axis of rotation (R) of the pivoting roller (08) within a travel path of at least one conveyor belt (04) between a first end face and a second end face of the pivoting roller (08), and/or that both a starting position and at least one pivoted position of the at least one pivoting roller (08) are arranged within a plane perpendicular to the pivot axis (S) and/or that an opening angle of the pivot axis (S) of the pivoting roller (08) with respect to the transport plane is at least 40° (forty degrees) and no more than 140° (one hundred and forty degrees).
 66. The sheet-processing machine according to claim 64, characterized in that the at least one pivoting roller (08) has a cylindrical shape and/or that the at least one infeed roller (06) and/or the at least one diverting roller (07) and/or the at least one tensioning roller (09) have a cylindrical shape or at least one feed roller (06; 07; 09) of the feed rollers (06; 07; 08; 09) which differs from the pivoting roller (08) has a convex or conical shape.
 67. The sheet-processing machine according to claim 64, characterized in that the at least one transport unit (02) comprises at least one revolving conveyor belt (04).
 68. The sheet-processing machine according to claim 67, characterized in that, proceeding from the movement direction, pivoted with respect to the pivot axis (S) in a mathematically negative sense of rotation, the pivot axis (S) of the pivoting roller (08) has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees) with respect to a movement direction of the at least one conveyor belt (04) entering the pivoting roller (08), or that, proceeding from the movement direction, pivoted with respect to the pivot axis (S) in a mathematically positive sense of rotation, the pivot axis (S) of the pivoting roller (08) has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees), with respect to the movement direction of the at least one conveyor belt (04) entering the pivoting roller (08).
 69. The sheet-processing machine according to claim 67, characterized in that the pivot axis (S) of the pivoting roller (08) is situated parallel to the movement direction of the at least one entering conveyor belt (04) and/or that a wrap angle of the at least one conveyor belt (04) around the pivoting roller (08) is no more than 120° and/or at least 60° and/or that the at least one conveyor belt (04) is configured as a suction belt.
 70. The sheet-processing machine according to claim 64, characterized in that at least one feed roller (06; 07; 08; 09) of the feed rollers (06; 07; 08; 09) comprises grooves and/or microgrooves in the direction of rotation of the feed roller (06; 07; 08; 09), and that the grooves and/or microgrooves extend symmetrically from the center of the feed roller (06; 07; 08; 09) to its end faces.
 71. The sheet-processing machine according to claim 64, characterized in that at least one feed roller (06; 07; 09) of the feed rollers (06; 07; 08; 09) which differs from the pivoting roller (08) comprises a drive for driving the at least one conveyor belt (04).
 72. The sheet-processing machine according to claim 71, characterized in that the feed roller (06; 07; 09) comprising the drive for driving the at least one conveyor belt (04) has a cylindrical shape and/or that the at least one feed roller (06) configured as an infeed roller (06), which is arranged as the first feed roller (06) of the feed rollers (06; 07) along a transport path of sheets, or the at least one feed roller (07) configured as a diverting roller (07), which is arranged as the last feed roller (07) of the feed rollers (06; 07) along the transport path of sheets, or at least one further feed roller (09) configured as a tensioning roller (09), comprises the at least one drive.
 73. The sheet-processing machine according to claim 67, characterized in that at least one feed roller (09) of the at least two further feed rollers (08; 09) is configured as a tensioning roller (09), which differs from the further feed roller (08) configured as a pivoting roller (08), and is arranged upstream from the pivoting roller (08) in the movement direction of the at least one conveyor belt (04), that at least one tensioning device for tensioning the at least one conveyor belt (04) is provided outside the transport plane, that the at least one tensioning roller (09) is configured as an entering roller of the at least one tensioning device for tensioning the at least one conveyor belt (04), and that the at least one pivoting roller (08) is provided as an exiting roller of the at least one tensioning device.
 74. The sheet-processing machine according to claim 67, characterized in that at least one tensioning device for tensioning the at least one conveyor belt (04) is provided outside the transport plane, that the at least one tensioning device comprises at least one energy accumulator and/or that the at least one tensioning device is configured so as to pneumatically adjust and/or control the tensioning force against the at least one conveyor belt (04), and/or that the at least one tensioning device comprises at least one spring system (24) or at least one rocker arm (22) or at least one linear guide (23).
 75. A method for the straight-tracking guidance of at least one conveyor belt (04) of a sheet-processing machine, the at least one conveyor belt (04) being guided around at least one feed roller (06) configured as an infeed roller (06) and at least one feed roller (07) configured as a diverting roller (07), the at least one infeed roller (06) and the at least one diverting roller (07) defining a transport plane of sheets, the at least one conveyor belt (04) being guided around at least two further feed rollers (08; 09) of the transport unit (02) outside the transport plane, at least one feed roller (08) of the at least two further feed rollers (08; 09) configured as a pivoting roller (08) pivoting about a pivot axis (S), and the pivot axis (S) of the pivoting roller (08) being an axis normal of an axis of rotation (R) of the pivoting roller (08), characterized in that the at least one pivoting roller (08) pivots automatically about the pivot axis (S).
 76. The method according to claim 75, characterized in that the at least one pivoting roller (08) is pivoted about the pivot axis (S) by a belt tension of the at least one conveyor belt (04) and/or that the pivoting roller (08) pivots about the pivot axis (S) situated along an axis of rotation (R) of the pivoting roller (08) within the travel path of the at least one conveyor belt (04) between a first end face and a second end face of the pivoting roller (08) and/or that the at least one conveyor belt (04) is guided over the at least one cylindrical pivoting roller (08) and/or that both a starting position and at least one pivoted position of the at least one pivoting roller (08) are arranged within a plane perpendicular to the pivot axis (S).
 77. The method according to claim 75, characterized in that, proceeding from the movement direction, pivoted with respect to the pivot axis (S) in a mathematically negative sense of rotation, the pivot axis (S) of the pivoting roller (08) has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees) with respect to a movement direction of the at least one conveyor belt (04) entering the pivoting roller (08), or that, proceeding from the movement direction, pivoted with respect to the pivot axis (S) in a mathematically positive sense of rotation, the pivot axis (S) of the pivoting roller (08) has an angle of at least 0° (zero degrees) and/or of no more than 20° (twenty degrees), with respect to the movement direction of the at least one conveyor belt (04) entering the pivoting roller (08), and/or that the at least one conveyor belt (04) wraps around the pivoting roller (08) at a wrap angle of no more than 120° and/or at least 60° and/or that an opening angle of the pivot axis (S) of the pivoting roller (08) with respect to the transport plane is at least 40° (forty degrees) and no more than 140° (one hundred and forty degrees).
 78. The method according to claim 75, characterized in that at least one feed roller (09) of the at least two further feed rollers (08; 09) configured as a tensioning roller (09), which differs from the further feed roller (08) configured as a pivoting roller (08), is arranged upstream from the pivoting roller (08) in the movement direction of the at least one conveyor belt (04), that the at least one conveyor belt (04) is tensioned by at least one tensioning device for tensioning the at least one conveyor belt (04), that the at least one tensioning roller (09) is configured as an entering roller of the at least one tensioning device for tensioning the at least one conveyor belt (04), and that the at least one pivoting roller (08) is provided as an exiting roller of the at least one tensioning device. 